Telephone system



M ay 17 1927.

w. M. BEAUMONT ET AL TELEPHONE SYSTEM f Filed Aug. 2o, 1925 ffl/enfans. M//fam M eaa//fa/Wf fe//X A. 5000/7. hiv WQMM. My

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subscribers line i Patented May 17, 1927.

'r ES 1,629,015 PAT-ENT orifice.

WLLIAM M. BEAUIVIONT, OF SUMMIT, NEW JERSEY, AND FELIX A. BONOM'I, OF BROOKLYN, NEW" YORK, ASSIGNORS TO WESTERN ELECTRIC COMPANY, INCOR-f PORATED, F NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE SYSTEM.

Application filed August '20, 1925. Serial No. 51,2978.

This invention relates to telephone systems and more particularly to improvements in. the supervision of trunlring or toll line connections.

1n systems of this type connections are usually extended from calling subscriber to toll operators switchboards and from there by way of so-called switching trunks leading to trunk operators or so-called B operators7 switchboards or positions from which connections are completed to a wanted subscriber line.

An object of this invention is to provide circuit arrangements whereby the supervision of the above and similar typesof connections at the B operators position is greatly improved.

To `attain this and other objects of the invention as will hereinafter appear, there is provided in accordance with one feature thereof, means at the B operators position whereby if a connection, incoming over a switching trunk, is to be extended to a busy subscribers line and the B operator inserts the plug of this. switching trunk into the .jack of said busy subscribers line the usual guard lamp signal is maintained operated and a busy tone isfestablished for the B operators ltelephone set to identify the switching trunk used and to indicate to .the B operator that this subscribers line Ais busy.

ri"he invention has been illustrated in the accompanying drawing in which circuits for extending a connection from .a .calling su`bscribcfs line 1 through a cord 2 vat a toll operators position to the aclr 3 ofa switchin;-` truuk 4e has been shown diagrammati- Y l 'cai The circuits of the lncoming end or this switching trunkfat the B operators ion are shown in detail and embody various features of invention. A master key and party line ringing circuit 5 accessible to a plruality of switching trunks is shown below the dash dotted line. A subscriber-"s line 6 has also been shown termin atiug in the usual multiple jack 7 at this ll operators position and by means of which a connection Yfrom the switching trunk Al, through plug El, may be connected to the subrjicribefs line 6.

Tilo make clear the functions of the invention yas applied to a circuit arrangement of this type, a connection between the calling `and the subscr1`be1"s hue 6 over the switching trunk t when this called subscribers line is idle will lirst be described followed by a description of a connection to the subscribers line 6 when this called subscribers line is engaged at ak is desired over i this particular switchingy trunk, by connecting the tip and vring conductors of the switching trunk together as is well known in the art, a circuit will be completed as follows:

F rom battery, lower winding of relay 10 make before break contacts of relay 11, lower left hand winding of repeating coil 12, over the ring conductor of switching trunk 4 through the loop at the toll operators position, over the tip conductor of switching trunk 4, `upper left hand winding of repeating coil 12, upper armature of back contact or relay 11, upper winding of relay 10 to ground. This vcauses the operation of relay 1'() which now completes the following circuit :r Battery, guard lamp 13, lower outer armature and hack contact of relay 111, armature and front contact of relay 10 to ground, causing the lighting of guard lamp 13 associated with plug 8 to indicate to the B Yoperator that a connection is desired over this particular switching trunk. Theoperation of relay 10 also closes a circuit for relay 11 as follows: Battery, outer .right hand armature and back contact of relay 15. vupper winding'of relay 11, armature and front contact of relay 10 to ground. Relay 11 in energizing opens the above mentioned circuit .through the windings of relay 10 at the make vbefore break contacts upper armature and back contact of relay 11 but closes an obvious 'holding circuitthrough the lower winding of rela-y 10 at the lower armature and front contact of relay 11 so that this relay V10 will be maintained operated as long as relay 11 remains operated. The opening of the circuit to the toll operators position causes a sional to be given to the toll operator in a. lnanner well known to the art to indicate to the toll operator that the B operator has been signaled to the effect that a connection is desired over this switching trunk.

As is well known in rnodern toll practice the B operator has previously been notified by the toll operator over the usual call wire of the nuinber of the subscribers line wanted so that the B operator will now test jack 7 of line 6 in the usual inanner by touching the sleeve of jack 7 with the tip of plug 8. lf the wanted subsciibei"s line is idle, the l5 operator inserts plug 8 1n Jack 7 causing the following` circuit to be closed: Battery, winding of relay 111, sleeve conductors of plug 8 and jack 'l' to ground causing the operation of relay 14. The operation of relay lll disconnects the busy test lead; completes the tip conductor froin the plug S to the upper winding of repeating coil 12 to ground; opens the circuit for the guard larnp 13 and closes at its lower inner armature and front contact a circuit for relay 16 as follows: Battery, winding of relay 16, make before break contacts of relay 15, lower arn'iature and front contact of relay 14 to ground which causes the operation of relay 16. This relay in operating completes at its armatures and front contacts connections to the niaster ringing key circuit 5, which is connnon to a plurality of switching trunk circuits such as Il, for various purposes as will hereinafter be described. rllhe operation of the outer left hand armature of relay 16 closes a circuit froni battery at the front contact of this arinature through the winding of relay 17 to ground which causes the operation of relay 17. The operation of this relay closes, at its lower arinature and front contact, an energizing circuit for a inasier ringing signal 1S, which indicates to the B operator that the nlasler key circuit 5 is associated with a trunk.

r1`he B operator now impresses the ringing key corresponding` to the particular party wanted on the subscribers line 6. For example if the party M or the party J is desired, the operator depresses either key 19 or key 40. If it is assumed the party M is the one desired a circuit is coinpleted frorn battery, winding of key 19, lower arinature and back contact of relay 2l to ground, which causes the operation of relay 2U. This relay in operating provides a locking circuit for itselirl through its lower armature and a front contact to ground at the lower inner arinatnr'e and front contact of relay 17. The operation of relay also closes the circuit for relay 23 as follows: Battery, winding of relay 23, outer right hand armature and front Contact of relay 16, upper' arinature and front contact of relay 2() to ground. This circuit causes the operation of relay 23 which now provides a locking circuit for itself through its upper inner armature and front contact to ground at the lower' inner armature and front contact of relay 14 and also provides a connection at its upper outer armature and lower arinature and front contacts for the ringing source 24 and ground 25 for purposes as hereinafter described. The operation of relay 2O also closes at its front contacts 26 a circuit for the operation-of relay 27 as follows: Battery, winding of relay 27, contacts 26, key 19, lower armature and back cont-act of relay 21 to ground. l`he operation of this relay closes a circuit for the o )eration of relay 15 froin battery, winding of relay 15, inner right hand ar- .inature and front contact of relay 16, armature and front contact of relay 27, lower inner armature and front contact of relay 12' to ground. relay 15 provides a locking circuit for itself through its inner right hand armature and front contact to ground at the inner lower armature and front contact of relay la. The operation of relay 15 opens at its inake before break contacts, the circuit for relay 16, which is now released and in releasing causes the release of relay 17 and opens the locking circuit for relay 9,0 and the energizing circuits for relay 15. The release of relays 2O and 16 opens the original circuit of 23 but relays 15 and 23 do not release as they are both locked in operated position under control of the ground at the inner lower armature and front contact of relay 14. The operation of relay 15 opens at its outerright hand armature and back contact the energizing circuit for relay 11 so that this relay is released and closes the connection froin the switching trunk lead's to the battery and ground through the windings of relay 10. The closing of this circuit causes, in a inanner well known in the art, a signal to be lighted at the toll operator-s position, this signal indicating to the toll operator that the switching trunk has been prepared by the l5 operator for the ringing of the party desired on the subscribers line 6.

As is well known in the art, the toll operator now causes a ringing signal to be transinitted to the desired party by applying current froin an alternating current source to the conductors of trunk l thus causing the operation of the alternating current responsive relay 2S. If, as assuined, the party M of the line 6 is wanted this relay is operated one@`J but if party J is wanted this relay is operated twice in succession. ln 'this case relay 28 will operate but once and the operation of this relay closes a circuit for relays 29 and 11 as follows: Battery, lower winding of relay 11, winding of relay 29 arinature and front contact of relay 28 to ground. The operation of relay 11 opens the circuit igeagoif through the windings ofrelay 10 as hereto. foredescribed, which thus causes the signal at the toll operators position to be extinguished to indicate that the. party Monthe wantedv subscribers .line 6 is rung. The oper-- ation-of relay 29 closes a connectionat its.

armatures and :front contacts from the ring ing source 24 and ground l25'over the tip and ring conductors, respectively, through plug. 8 and jack -7 and `'the subscribers .line .6 to the bell .offthe wanted party. M. If party J hadv been the subscriber wanted by the t0llzoperator,'this.operator would, as hereinbefore stated, have operated relay 28twice and consequently caused the operation of relays 11 and 29 twice and the signal at the toll operators position would then have been similar- 1y operated and the partyJ vby receiving two rings would have known that he was the back contact of relay 29, ringterininals of' plug S and jack7 overlsubscribers loop to the tip terminals ofackl 7 and plug 8,' upperl armature 'and front contact of relay 14, upper armatureand backcontact of relay 29, upper right hand .winding of repeating coil l2 to ground. Thiscircuit causes-the oper ation of relay 30 and this .relay in operating closes a circuit thirouglrthe two windingsof relay 11 in series as'follows: Battery, lowerr winding of relay 11, armature and lfront contact vof relay 30,upperwindinglofrelay 11,'l

armature andfront contactxoffrelay 10A to ground. This causes'relay 1l Ato operate and again. open .the connectionfor theswitchi-ng trunk to the toll operators position to ex#v tinguish, the signal .lamp thei'eat-as an indicationnthat the wanted subscriber has answered the call.

if thewanted. subscriber desires to cally the operator afterhaving beenlonce connected, he may operate his switchhook up and-'down and thus open. and. closethe subscribers' lineV loop causing the voperation and release of re- I lays SGand 11 `and thus correspondingly eX- tiiiguisli and reli'ght the signal at thetoll operators position and therebyy call -this operators attention tothe connection.

It should be noted that in case the wanted subscriber. is either lthe party R or .the party lV, the corresponding keys 41 or 42 are de- Dressed and the corres 9ondinOrela s 32 or- Swwill'be operated in the saineinanner -as were relays 2O or 3l. In, this instance, howL ever,L relay123 will not be operated and the connection.froniethe ringing source 24 and* ground 25 will'not be established 1n the saine manner as in the casewhere the parties Mor Iwere wanted, but the ringing source 24 will in this case remain connected to the ring side ofthe, line 6 and the ground 25 to the tip side of the; line` 6, sothat when :the toll operator rings either of these parties by.. operating, relay 28 .once or twice. either= of these parties will be. signalled "with current applied inthe reverse vInannerto the line.

The connection is now completed through to the wanted subscriber andthetoll operator lias'in the meantime, as iswell known in theA art, extended theconnection to the called subscriber so thatconversation between these subscribers can lnow begin. v

vWhen the Vconversation .is ended the called on the hook and thus releaselrelay@ causing therelease of relay 11. Release of this latter:

relay closes Vthe circuit through relayy 10 to the switchingtrunk and the toll operators position. and the signal thereat is lighted to indicate that the called subscriber is finished with'.theconnection The toll operator may then reinove the calling plug. off'cord circuit 2 from jack 3 thus `causing relay 10 torelease. A circuit for the, guard lamp 13r is thereby closed and this lainpy lighted to indicateto the B voperator that ythe subscriber has hung up and Vthat the tollv operator hasdisconnected. TheB operator then :removes` plug .8 from jack 7 causing :the release oferelayv 14 which"extinguishesthe lamp 13-'land causes .the release of relay 15andf also relay' 28,.if1this relay is operated as'it'wouldbe in the case assumed, so thaty the. switching trunlr circuit is-now restored to normal pos-i.-

- If in. the case. assumed the subscribers.

line 6 had `tested busy, the B'operator 'will insert plug 8 in the usual busy back jack` (not shown) and thereby `cause a busy signal to be transmitted to the toll operator-sposition-.as follows: The insertionv of this plug Sintov such a vbusyjack will cause the operation' of relay 14 whichI in turn causestlie operationof relay 161thusconnecting the common master ringing key circuit 5 to the switching trunk 4.l The B operator now operates the key 35 causingthe energization of relayBG. This relay provides Va locking circuit for itself throughl relay 17 which is also operated as heretofore. 1 Thel-operation of relay 36 closes a circuit for relay 15 as follows: Battery, winding ofrelay 15, inner right hand armature and front contact of relay 16, upper armature andl front'contact of relay- 3G to ground. The

operation of relay 15 causes the'release of relay 16 vso thatthe master ringing keys 5 are disconnected from the switching trunk Y 4.l-j The operation ofrelay 15 also completes` a--circuit through the' tip and. ring? leads ofV thewb'usy back'jack,,whichy are vrlooped for tl'ievopera-tion of relay'30. Relay O-'irroperF ating closes a circuit for relay 11 thus opening the trunk circuit 4 to the toll operators position causing the signal at the tool operators position to be extinguished indicating at this stage of the connection that the wanted subscribers line is busy.

It, on the other hand, the connection from the toll operators position over switching trunk 4 must be extended over the subscriber-s line 6, regardless ot the 'tact that a party on this line is engage-d in another connection, the B operator will insert plug 8 in jack 7 causing the operation of relay 14 as herebefore described. The operation of this relay causes the operation of relay 16 and the association ot the master ringing key circuit 5 with a switching vtrunk to take place. As the subscribers line 6 is connected through another circuit, such as the trunk switching circuit 4 or an ordinary cordcircuit, a circuit will now be completed as follows: From battery through the winding of the relay corresponding` to relay 30, lett hand armature and iront contact ot the relay corresponding to relay 15, the lower right hand winding of the repeating coil corresponding to repeating coil 12 over the ring conductor ot the corresponding switching trunk through the ring terminal of the plug 8 through theJ ring conductor of switching trunk 4, lower armature and back contact of relay 29, lower right hand winding of repeating` coil 12, left hand armature and back contact of relay 15, winding ot' relay 21 to ground. This circuit causes the operation ot' relay 21 which now closes a circuit for maintaining lamp 13 lighted as follows: Battery, lamp 13 'lower outer armature and front contact of relay 14, inner lett hand armature and front contact of relay 1 6, lower armature and front contact of relay 21 to ground. rlhe maintenance of this `lamp 18 lighted at this stage of the connection serves as an indication to the B operator that this particular switching trunk is engaged to the busy line. rlhe operation of relay 21 also closes by its upper armature and front contact a circuit from the busy tone source 37 through the usual busy test winding of the B operators telephone set which may be connected at 88. rlhe tone transmitted over this circuit to the operators telephone set serves as an indication to the B operator that a busy line is involved in the connection. rJ''he B operator now prepares the switching trunk 4 lior ringing by the toll operator ot the desii-ed party on line 6. To this end the key in the master ringing signaling circuit 5 otl the particular party desired is operated and also the no test7 key 39 as it will be noted that relay 21 in operating disconnected the ground 'for the operating circuits for the relays associated with the master ringing keys so that whichever party line ringing key is operated the corresponding relay will have its operating circuit completed through the contacts of key 39. The operation ot the circuit to prepare the switching trunk for the ringing and the ringing by the toll operator of the desired party is identical with that hereinbefore described for the establishing of a connection to an idle subscriber on line 6. lt should be noted, of course, that on the release of relay 16, the master ringing key circuit 5 is disconnected from the switching trunk 4, the signal j13 extinguished and the tone from source 3'? to the operators telephone circuit discontinued.

Vilhatis claimed is:

1. In a telephone system, subscribers lines, a trunk comprising a signal, means tor operating said signal responsive to the seizure of said trunk, means for disabling said signal responsive to the connection of said trunk to an idle line, means for maintaining said signal operated responsive to the connection of said trunk to a busy line and means tor disabling said sional responsive to the signaling of the subscriber on the busy line.

2. In a. telephone system, subscribers lines, anoperators telephone set, a trunk line comprising a signal, a tone device, means for operating said signal responsive to seizure or' the trunk and means for maintaining said signal operated and for actuating the tone device to transmit a signal from said tone device to the operators telephone set responsive to the connection of said trunk line with a busy subscribers line.

3. In a telephone system, subscribers lines, an operators telephone set, a plurality of trunk lines, a ringing key circuit common to said trunk lines, a signal associated with each trunk line, a tone device associated with the ringing key circuit and the operators telephone set, means for operating a signal responsive to the seizure of the corresponding trunk line and means for maintaining said signal operated, for associating said ringing key circuit and tone device with said trunk line and for actuating said tone device to transmit a signal to the operators telephone set responsive to the connection of said trunk line with a busy subscribers line.

4. ln a telephone system, subscribers lines, an operators telephone set, a plurality of trunk lines, a ringing key circuit common to said trunk lines, a signal associated with each trunk line, a tone device associated with said ringing key circuit and the'operators telephone set, means for operating said signal responsive to the seizure ot the corresponding trunk line, means for disabling said signal responsive to the connection of the corresponding trunk line with an idle sub-` scribers line and means for maintaining said signal operated, for associating said ringing key circuit and tone device with said trunk line for actuating Said tone device to transmit a signal to the operators telephone set responsive to the connection of said trunk line to a busy subscribers line.

5. In a-telephone system, subscribers lines, an operators telephone set, a plurality of trunk lines, a ringing key circuit common to said trunk lines, a signal associated with each trunk line, a tone device associated with said ringing key circuit and the operators telephone set, means for operating a signal responsive to the seizure of the corresponding trunk line, means for maintaining said sig- "5 nal operated, forassociating said ringing key circuit and tone device with said trunk line and for actuating said tone device to transmit a signal to the operators telephone set responsive to the connection of said trunk line with a busy subscribers line, and means for disabling said signal and tone device and disconnecting the ringing key circuit from the trunk line responsive to the operation of a key in said circuit.

In Witness whereof, we hereunto subscribe our names this 17th day of August A. D., 1925.

WILLIAM M. BEAUMONT. FELIX A. BONOMI. 

